Vibration-absorber for alternating-current-magnet armatures.



v G. L. ROSENQVIST. VIBRATION ABSORBER FOR ALTERNATING CURRENT MAGNET ARMATURES.

I APPLICATION FILED AUG. 21, 1908.

U I g.2.

Patehtd Jan.9,1912.

. character of the current supplied to it. 'As

. to another, and is particularly adapted for I use with alternating current electro-magnets UNITED STATES BgENT OFFICE.

CONRAD L. ROSENQVIST, OF YONKERS, NEW YORK, ASSIGNOR TO OTIS ELEVATOR COMPANY, OF JERSEY CITY, NEW JERSEY, A CORPORATION OF NEW JERSEY.

VIBRATION-ABSORBER FOR ALTERNATING CURRENT-MAGNET ARMAT'ITRES:

Application filed August 21,

Patented J an. 9, 1912.

1908. Serial No. 449,687.

To all whom it may concern:

Be it known that I, CONRAD L. ROSEN- ovrsr, a subject of the King of Sweden residing in Yonkers, in the county of lestchester and State of New York, have invented a new and useful Improvement in Vibration-Absorbers for Alternating-Current-Magnet Armatures, of which the fol lowing is a'specification- The present invention relates to means for absorbing or counteracting mechanical vibrations in one body by transferring them or other apparatus or parts of mechanism where it is desirable to stop or reduce the vibrations of certain parts An object of the invention is to provide means to reduce to a minimum the vibrations set up in a body, as, for example, the armature core of an electro-magnet energized by a single phase alternating current.

It is well known that 'the armature or moving part of an electro-magnet energized by a single phase alternating current vibrates more or less,' due to the pulsating these vibrations produce noise and cause considerable wear on the pins or center screws which support the movable'part of the magnet, it is desirable that these vibra-- tions be reduced to a minimum, and I pro-' pose to accomplish this result by'pro'ducing in an attached body a secondary set of vibrations that differ in magnitudeand phase, butnot in rate from those of the magnet; This result may be secured by having git-' tached to the armature or vibrating body as elastic vibratory transmitter having secured to it a suitable counterweight.

Other objects of the invent-ion will appear hereinafter, the novel combinations of elements being set forth in the appended claims.

Referring to the accompanying drawings, in which are illustrated several forms of construction embodying my invention, Figure 1 is a side elevation of an electro-Inagnetic switch mechanism to which the invention is applied; Fig. 2 is a rear elevation of the same; Fig. 3 is a side elevation of a modification; and Flg. 4 is a detail view of a modified form of the device for absorbing vibrations.

As shown in FigsQl and 2, a base-plate 1 of slate or other suitable insulating material has secured to its front and'rear faces, respectively, the bracket plates 2 and 3. A switch lever 4, pivoted at 5 tothe bracket plate 2, carries at its upper end a contact 6 adapted to be moved into and out of engagement with a stationary carbon contact 7 The magnet frame 8 is preferably made of laminated soft iron and is formed with a central core 9 surrounded by the magnet coil 10. The armature 11, also made of laminated magnetic material, is carried by' a lever 12 which extends through an opening in the base 1 and is pivoted at 13 to the bracket plate 2. A depending lug 14 on the lever 12 is adapted to strike a bolt or, projection-15 on the switch lever at and open the switch when the armature is dropped. A coil spring 16 which bears against the lower end of thesw-itch lever closes the switch when the armature 11 is in its attracted position. A- buffer 17 of leather, rubber, or other suitable'material may be placed be-( tween the magnet frame and the armature lever 12 in position to hold the armature separated a slight distance from its magnet. The magnet is adapted to be energized by a single phase alternating current, and in order to eliminate or reduce to a minimum the vibrations set up in the'armature, I provide the following device; An elastic member 18 which as here shown is in the form of a flat metal spring curved into a U shape, has secured thereto at one end a counterweight;19. The other end of the elastic member is secured to the outer end of the armature lever by means of a bolt 20. Now

a weight supported in this manner, if moved.

so as to place the spring under tension and then released, will vibrate at a substantially uniform rate, the amplitude of vibration gradually decreasing until the weight comes to rest. This normal rate of vibration depends on several factors, such as the length of the spring, mass of the weight, and strength or stiffness of the spring, and by varying any of these factors the .normal rate of Vibration may be varied. The vibrations of the weight are transmitted through the spring and tend to produce vibrations in the support corresponding in rate, but not in 6 phase, with those of the weight. Also, vi-

brations of the support will be transmitted through the spring 18 to the counterweight g;

and cause it to vibrate if the rate of vibrationof support is the same as the normal 110.

7 -.contact 6".

40 pieces of a vertical 55 part to which it is attached.

rate of vibration of the counterweight. In the present OOIlSlSIllCiJlQH, the counterweight and elastic member are so designed that the normal rate of vibration will be the same as that of the armature, due to current alternaa tlons.- The best results are obtained when the counterweight is lighter than the armature, and the-elastic member 18 is so pro'-' portioned that the vibration or movement '10 of the counterweight will be nearly inyan to that of the armature opposite direction at any given time. With this arrangement it isevident that during the period of the cycle when the current is at or near the zero-point,

and the magnet tends to drop its armature;

the stored energy of the counterweight is utilized to keep the armature in place" until the next current impulse reaches the 'working value,.and thus the tendency of the arma- 20 ture to vibrate is checked by the countervibrations of the weight 19.

In Fig. 3 I have shown another of,

magnet to which my invention is applied.

In this case themagnet frame 8 position: The stationary contact 6" of the switch is secured to the base 1, and'the'movable contact 7 isprovided with a stem 27 extending through openings in the vertical extensions 28 and 29 of the magnet frame andarmature, respectively. A coilspring30 surrounds the stem 27 betwen the, extension 28. and the contact-7' and normally holds said contactin engagement with "the fixed A comparatively heavy coil springffii surrounding the stem 27 between the extensions 28- and '29 holds the pole of the magnet and armature slightly separated and also serves to absorb or par tially absorb the vibrations of the armature. v is deenergized the arma When the magnet I ture swings outward about the pivot 26 and the extension 2Qstrikes'the' nuts 32 on the.

stem 27 and moves the contact? 'awa from the fixed contact 6" to open the switc The counterweight 19' and elastic member 18% are similar to the parts 18 and 19 of Fig. 1, '50 but are arrangedto ermit the counterweight a horizontal direction instead direction as in Fig. 1.- In each case the weight is arranged to vibrate in the samedirection as'the armature or vibrating to..- vibrate in In Fig. 4 is shown a modified form of the vibration absorber. The elastic member 18" is in this instance a coil spring connected at one end to a counterweight 19 and adapted to be connected. at its opposite end to the armature or other vibratory member.

The particular forms of vibration absorbis secured.

25 to thebase 1 by bolts 25. The armaturel l v is pivoted at 26V to the magnet frame and is: approximately! vertical whenin its attracted current, a-vibratory ers shown are merely examples of the various forms which comewithm thescope ofthe present invention. The elastic member may e made in many difierent ways and forms 'Lother than those shown on the drawing. The

p injt. of attachment of, the elastic member to thdvibrating part may also be varied wi'thin wide limits. It will be understood furtherthat the invention may have a much wider a plicati'dii than to alternating cur- .rcnt i'na nets alone, as in general it may be Letters ,Patent of the United States is member, ofelectro-magnetic means for producing a uniform rate of vibrations thGIGHI and an attached body having the same nor- "mal rate. of vibration as sand memberand.

adapted to'vibrate in opposition thereto.

" 2. The vcombination with 'a-ifvibratory' member, of electromagnetic'means'for roducing vibrations. therein, "and-an "attac vibratory body phase.

adapted tb be energizedbyan alternatin current, and a mechanical-device connecte thereto and adapted to decrease the mechanical 'vibratlons, in :said .[electro-magnet by means of counter-vibrations. a '4. The combination. with 'an alternatlng current magnet and" its armature, of a edhaving the same. rate; of vibrations as saidmemben-butldiifering in' 3. The combinationjoffan electro-magnet weight, and anelastic"vibrationtransmitter I 1 connecting said weight and armature;

35. Thecomb'n'ation' with an alternating current 'electro-magnetg a *vibratorf body,

and means for reducing thel yibra ions of the electro-magnet. due .;;to current alternations by transmitting .cou'nten vibrations from said'body-to the, electrosmagnet'.

-- 6- The combination with an electro 1magnet "adapted 'to. he vibrated by an alternating ducing in'said body counter vibrations differing in phase from those of the magnet.

In testimony whereof, I have-signed my name to this specification in the presence of two subscribing witnesses.

(JOE-RAD L. ROSENQVIST.

Witnesses; I

EDWARD H. STEELE,

H. MARSDEN.

topics of this patent may I:

e obtained for five cents each, by addressing thc"(3oinmissioner of IPaten ts,

1 Washington, D. G.

body, and means for;re-'

ducing the vibrations of the magnet by pro T 115. 

